CH. iv] VARIATIONS IN MORPHOLOGY 41 



of B. typhosus, B. coli, B. pyocyaneus, B. enteritidis Gaertner, 

 and B. pneumoniae Friedlander ; Adami, Abbott and Nichol- 

 son, by the addition of human saliva, or a trace of bile, 

 obtained the same result with B. coli. Growth in an acid 

 lactose containing medium also developed filamentous forms 

 of this organism. They quote Schmidt's observation that 

 growth in caustic soda broth had the same effect. 



Adami (1892) observed that B. pyocyanem took the form 

 of a filament or, in some cases, developed into close spirals and 

 S-shaped forms under the influence of /9. naphthol, alcohol, 

 potassium bichromate, boric acid ; and Pakes (1901) noted that 

 the nitrates of sodium, potassium, ammonium, and lithium 

 developed in the same organism filamentous forms which 

 showed spurious branching and resembled a cladothrix. 



Wasserzug (1888) found that B. prodigiosus formed long 

 bacilli and spirilla if grown in the presence of antiseptics. 

 Tartaric acid had the same effect and by prolonged growth 

 in media containing this acid and subjection to a temperature 

 of 50 C. subsequently for a few minutes, a race of long bacilli 

 was obtained which retained its new character "permanently" 

 that is to say on its return to ordinary media. 



2. The formation of zoogleae may be provoked by alteration 

 in temperature. Rodet (quoted and confirmed by Adami, 

 Abbott and Nicholson, 1899) found that a culture of B. coli 

 at a temperature of 44-45 C. developed within a few hours 

 very long filaments. 



3. The absence of oxygen may have the same effect. Wood 

 (1889) observed "torula" forms of the cholera bacillus when 

 grown in bouillon anaerobically. Noguchi (1910) found that 

 B. bifidus communis only exhibited its bifurcating phase in 

 anaerobic culture. 



4. Exposure to the ultra violet rays leads to the formation 

 of long filaments in B. anthracis (Henri, 1914). 



5. Growth in the animal body develops on the part of the 

 actinomyces its characteristic rays or clubs. These are not 

 seen in artificial cultures (Bowlby and Andre wes). 



